function login(){
   var account=document.getElementById('useraccount').value;
   var pass=document.getElementById('userpass').value;
   var randnumber=document.getElementById('randNumber').value;
   if(account==''){
	  	Ext.MessageBox.alert('系统提示',"用户账号不能为空！");
	  }
   else if(pass=='')
   {
	  	Ext.MessageBox.alert('系统提示',"用户密码不能为空！");
	  }
   else if(randnumber=='')
   {
	  	Ext.MessageBox.alert('系统提示',"验证码不能为空！");
   }
   else{
	   document.getElementById('logoutForm').submit();
   }
}

function reset(){
   document.getElementById('logoutForm').reset();
}